US2981832A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switching system
Assignee: IOWA STATE COLLEGE RES FOUND
•
Filing: 1958-10-21
•
Granted: 1961-04-25
•
Expires: 1978-10-21
Abstract
No abstract record available.
Inventors
- 👤 Roy H Mattson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:18
CPC Classifications
H; H01; H01H; H01H47/00; H01H47/02; H01H47/18; H01P; H01P1/00; H01P1/10; H01P1/15
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2403500A
Cited
US2497958A
Cited
US2688699A
Cited
US2439651A
Cited
US2618777A
Cited
US2552052A
Cited
US2618753A
Cited
US2657318A
Cited
US2782303A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-04-24 | 1964-10-24 | 1965-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-24 | 1968-10-24 | 1969-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-24 | 1972-10-24 | 1973-04-25 | $7700.00 | Window Closed / Lapsed |